This invention relates to a jumpsuit for controlled freefalling, and more particularly to a jumpsuit having expansible wing areas and means for controlling the expansion and contraction of the wing areas.
In the late 1960's the art of freefalling in skydiving began to attract increasing numbers of non-military participants. Although military jumpsuits and other skydiving gear were utilized originally, nevertheless, more personalized equipment was desired. Initially, commercial jumpsuit designs were merely replicas of the prevailing military products, which were essentially tight-fitting, with no specialized aerodynamic features.
However, as early as 1973-1974, the burgeoning sport of skydiving was attracting specialized manufacturing including new jumpsuits with features that permitted the wearer to exercise increased control over his rate of descent while freefalling from 100 to 200 miles per hour.
The initial aerodynamic features which instantly swept the market consisted of bloused sleeves and pant legs (a.k.a. bells), and wing areas. Such modified designs permitted freefalling at slower speeds because of the drag produced by the vibrant fluttering of loose fitting bell bottom and bell sleeve suits. The ability of the freefaller to retard his fall rate permitted him to exercise greater control in matching his fall rate with the other skydivers falling with him during the act of "relative work" which involves the building of assorted freefall formations by various numbers of jumpers.
Shortly after the introduction of belled suits, it was discovered that additional material could be included in the armpit area of the suit which could be pulled tight with a string fixed within the armpit area by fully extending one's arms. The taut armpit material produced an increased wing area under each arm from the wrist to the waist which would catch additional air, thereby creating more drag upon the suit to permit the jumper to attain a slower speed. This suit feature, commonly referred to as wings, swept the market along with bell legs and arms, and both features were included in virtually every jumpsuit manufactured in the late '70's and early '80's.
However, in the early to mid 1980's, the large suits with bells and wing areas created problems in the formation of large freefall patterns of jumpers, including up to 100 or more persons. The fall rate of various jumpers was erratic because of the unintentional, though unavoidable, stretching tight and then loosening of the bell and wing areas, which varied the individual jumpers fall rates thereby creating difficulty in forming the various sky patterns.
The existing wing areas in jumpsuits slow a jumper's fall rate primarily when the jumper exerts tension on the direct line from his wrist to his waist which is fixed at both ends. Although the wing area will cease to catch air when the jumper's arms are bent at the elbow to loosen the fixed extender lines, at times he must reach out to effect a particular maneuver, and thereby inadvertently extend the wing area. Also, other jumpers who grab one jumper's arms in freefall, inadvertently pull the wing area tight and slow that jumper's fall speed without the jumper's ability to control the contraction and expansion of the wing area.
Accordingly, since partial control of the wing surfaces in freefall maneuvers creates more problems than it solves, current jumpsuit designs have dropped the expansion feature entirely so that all jumpers will fall at a more uniform rate with no loss of control over the fall rate.